Automobiles have many different functions controlled by the operator. For example, the operator controls the engine, transmission, transfer case, steering, braking, lighting, doors and door locks, sound systems, wipers, heaters. Previously, such automobile functions were few and fairly simple devices coupled to the operator with various mechanical linkages. Subsequently, hydraulic systems and electrical systems were developed and replaced many of the earlier mechanical linkages or made it possible to include new functions that did not have mechanical equivalents.
Currently, many functions are electronic and permit further improvement in various automobile functions and subsystems. For example, brakes were originally mechanical and actuated by cables and wires coupled between the brake pedal and brake shoes. Hydraulic brakes replaced the mechanical brakes and electronically controlled brakes replaced the hydraulic brakes and provide numerous capabilities that did not previously exist, such as antilock braking capability and independent braking at each wheel.
Many other automobile control functions are also being converted from mechanical or hydraulically controlled functions to electronically controlled functions. These electronically controlled functions are referred to generally as drive-by-wire systems as the automobile control functions previously having direct mechanical or hydraulic linkage between the operator and n actuator (e.g., brakes, engine, transmission, lights, etc.) no longer exist or have only an auxiliary role and the operator exerts control over the particular function through an electronic controller. The electronic controller receives operator commands (e.g., turn left/right; speed up/slow down; apply/release brakes; lights on/off; etc.), translates the operator commands into electrical signals and sends the electrical signals to the appropriate actuator (e.g., steering motor; throttle actuator; brake actuator; light control module; etc.). The electronic controller may also make a variety decisions, including decisions to adjust one or more actuators to improve operational performance. Antilock brakes are a well known example of a drive-by-wire function that makes decisions that improve operational performance of the automobile.
In addition to improving operational performance of automobiles, drive-by-wire systems are continuously sought that have improved reliability. Since automobile drive-by-wire systems rely on electronic communication between control modules and actuators, the drive-by-wire systems are susceptible to interruptions in communication channels, which can be caused by any number of factors or events and ultimately reduce reliability. Thus, automobile drive-by-wired systems are continually sought that address the susceptibility to communication interruptions.
Accordingly, it is desirable to provide improved drive-by-wire systems for automobiles. It is especially desirable to provide automobile drive-by-wire systems having redundant electronic communication paths that minimize effects caused by interruptions in communication channels. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.